1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /************************************************************ 3 * EFI GUID Partition Table handling 4 * 5 * http://www.uefi.org/specs/ 6 * http://www.intel.com/technology/efi/ 7 * 8 * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com> 9 * Copyright 2000,2001,2002,2004 Dell Inc. 10 * 11 * TODO: 12 * 13 * Changelog: 14 * Mon August 5th, 2013 Davidlohr Bueso <davidlohr@hp.com> 15 * - detect hybrid MBRs, tighter pMBR checking & cleanups. 16 * 17 * Mon Nov 09 2004 Matt Domsch <Matt_Domsch@dell.com> 18 * - test for valid PMBR and valid PGPT before ever reading 19 * AGPT, allow override with 'gpt' kernel command line option. 20 * - check for first/last_usable_lba outside of size of disk 21 * 22 * Tue Mar 26 2002 Matt Domsch <Matt_Domsch@dell.com> 23 * - Ported to 2.5.7-pre1 and 2.5.7-dj2 24 * - Applied patch to avoid fault in alternate header handling 25 * - cleaned up find_valid_gpt 26 * - On-disk structure and copy in memory is *always* LE now - 27 * swab fields as needed 28 * - remove print_gpt_header() 29 * - only use first max_p partition entries, to keep the kernel minor number 30 * and partition numbers tied. 31 * 32 * Mon Feb 04 2002 Matt Domsch <Matt_Domsch@dell.com> 33 * - Removed __PRIPTR_PREFIX - not being used 34 * 35 * Mon Jan 14 2002 Matt Domsch <Matt_Domsch@dell.com> 36 * - Ported to 2.5.2-pre11 + library crc32 patch Linus applied 37 * 38 * Thu Dec 6 2001 Matt Domsch <Matt_Domsch@dell.com> 39 * - Added compare_gpts(). 40 * - moved le_efi_guid_to_cpus() back into this file. GPT is the only 41 * thing that keeps EFI GUIDs on disk. 42 * - Changed gpt structure names and members to be simpler and more Linux-like. 43 * 44 * Wed Oct 17 2001 Matt Domsch <Matt_Domsch@dell.com> 45 * - Removed CONFIG_DEVFS_VOLUMES_UUID code entirely per Martin Wilck 46 * 47 * Wed Oct 10 2001 Matt Domsch <Matt_Domsch@dell.com> 48 * - Changed function comments to DocBook style per Andreas Dilger suggestion. 49 * 50 * Mon Oct 08 2001 Matt Domsch <Matt_Domsch@dell.com> 51 * - Change read_lba() to use the page cache per Al Viro's work. 52 * - print u64s properly on all architectures 53 * - fixed debug_printk(), now Dprintk() 54 * 55 * Mon Oct 01 2001 Matt Domsch <Matt_Domsch@dell.com> 56 * - Style cleanups 57 * - made most functions static 58 * - Endianness addition 59 * - remove test for second alternate header, as it's not per spec, 60 * and is unnecessary. There's now a method to read/write the last 61 * sector of an odd-sized disk from user space. No tools have ever 62 * been released which used this code, so it's effectively dead. 63 * - Per Asit Mallick of Intel, added a test for a valid PMBR. 64 * - Added kernel command line option 'gpt' to override valid PMBR test. 65 * 66 * Wed Jun 6 2001 Martin Wilck <Martin.Wilck@Fujitsu-Siemens.com> 67 * - added devfs volume UUID support (/dev/volumes/uuids) for 68 * mounting file systems by the partition GUID. 69 * 70 * Tue Dec 5 2000 Matt Domsch <Matt_Domsch@dell.com> 71 * - Moved crc32() to linux/lib, added efi_crc32(). 72 * 73 * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com> 74 * - Replaced Intel's CRC32 function with an equivalent 75 * non-license-restricted version. 76 * 77 * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com> 78 * - Fixed the last_lba() call to return the proper last block 79 * 80 * Thu Oct 12 2000 Matt Domsch <Matt_Domsch@dell.com> 81 * - Thanks to Andries Brouwer for his debugging assistance. 82 * - Code works, detects all the partitions. 83 * 84 ************************************************************/ 85 #include <linux/kernel.h> 86 #include <linux/crc32.h> 87 #include <linux/ctype.h> 88 #include <linux/math64.h> 89 #include <linux/slab.h> 90 #include "check.h" 91 #include "efi.h" 92 93 /* This allows a kernel command line option 'gpt' to override 94 * the test for invalid PMBR. Not __initdata because reloading 95 * the partition tables happens after init too. 96 */ 97 static int force_gpt; 98 static int __init 99 force_gpt_fn(char *str) 100 { 101 force_gpt = 1; 102 return 1; 103 } 104 __setup("gpt", force_gpt_fn); 105 106 107 /** 108 * efi_crc32() - EFI version of crc32 function 109 * @buf: buffer to calculate crc32 of 110 * @len: length of buf 111 * 112 * Description: Returns EFI-style CRC32 value for @buf 113 * 114 * This function uses the little endian Ethernet polynomial 115 * but seeds the function with ~0, and xor's with ~0 at the end. 116 * Note, the EFI Specification, v1.02, has a reference to 117 * Dr. Dobbs Journal, May 1994 (actually it's in May 1992). 118 */ 119 static inline u32 120 efi_crc32(const void *buf, unsigned long len) 121 { 122 return (crc32(~0L, buf, len) ^ ~0L); 123 } 124 125 /** 126 * last_lba(): return number of last logical block of device 127 * @bdev: block device 128 * 129 * Description: Returns last LBA value on success, 0 on error. 130 * This is stored (by sd and ide-geometry) in 131 * the part[0] entry for this disk, and is the number of 132 * physical sectors available on the disk. 133 */ 134 static u64 last_lba(struct block_device *bdev) 135 { 136 if (!bdev || !bdev->bd_inode) 137 return 0; 138 return div_u64(bdev->bd_inode->i_size, 139 bdev_logical_block_size(bdev)) - 1ULL; 140 } 141 142 static inline int pmbr_part_valid(gpt_mbr_record *part) 143 { 144 if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT) 145 goto invalid; 146 147 /* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */ 148 if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA) 149 goto invalid; 150 151 return GPT_MBR_PROTECTIVE; 152 invalid: 153 return 0; 154 } 155 156 /** 157 * is_pmbr_valid(): test Protective MBR for validity 158 * @mbr: pointer to a legacy mbr structure 159 * @total_sectors: amount of sectors in the device 160 * 161 * Description: Checks for a valid protective or hybrid 162 * master boot record (MBR). The validity of a pMBR depends 163 * on all of the following properties: 164 * 1) MSDOS signature is in the last two bytes of the MBR 165 * 2) One partition of type 0xEE is found 166 * 167 * In addition, a hybrid MBR will have up to three additional 168 * primary partitions, which point to the same space that's 169 * marked out by up to three GPT partitions. 170 * 171 * Returns 0 upon invalid MBR, or GPT_MBR_PROTECTIVE or 172 * GPT_MBR_HYBRID depending on the device layout. 173 */ 174 static int is_pmbr_valid(legacy_mbr *mbr, sector_t total_sectors) 175 { 176 uint32_t sz = 0; 177 int i, part = 0, ret = 0; /* invalid by default */ 178 179 if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE) 180 goto done; 181 182 for (i = 0; i < 4; i++) { 183 ret = pmbr_part_valid(&mbr->partition_record[i]); 184 if (ret == GPT_MBR_PROTECTIVE) { 185 part = i; 186 /* 187 * Ok, we at least know that there's a protective MBR, 188 * now check if there are other partition types for 189 * hybrid MBR. 190 */ 191 goto check_hybrid; 192 } 193 } 194 195 if (ret != GPT_MBR_PROTECTIVE) 196 goto done; 197 check_hybrid: 198 for (i = 0; i < 4; i++) 199 if ((mbr->partition_record[i].os_type != 200 EFI_PMBR_OSTYPE_EFI_GPT) && 201 (mbr->partition_record[i].os_type != 0x00)) 202 ret = GPT_MBR_HYBRID; 203 204 /* 205 * Protective MBRs take up the lesser of the whole disk 206 * or 2 TiB (32bit LBA), ignoring the rest of the disk. 207 * Some partitioning programs, nonetheless, choose to set 208 * the size to the maximum 32-bit limitation, disregarding 209 * the disk size. 210 * 211 * Hybrid MBRs do not necessarily comply with this. 212 * 213 * Consider a bad value here to be a warning to support dd'ing 214 * an image from a smaller disk to a larger disk. 215 */ 216 if (ret == GPT_MBR_PROTECTIVE) { 217 sz = le32_to_cpu(mbr->partition_record[part].size_in_lba); 218 if (sz != (uint32_t) total_sectors - 1 && sz != 0xFFFFFFFF) 219 pr_debug("GPT: mbr size in lba (%u) different than whole disk (%u).\n", 220 sz, min_t(uint32_t, 221 total_sectors - 1, 0xFFFFFFFF)); 222 } 223 done: 224 return ret; 225 } 226 227 /** 228 * read_lba(): Read bytes from disk, starting at given LBA 229 * @state: disk parsed partitions 230 * @lba: the Logical Block Address of the partition table 231 * @buffer: destination buffer 232 * @count: bytes to read 233 * 234 * Description: Reads @count bytes from @state->bdev into @buffer. 235 * Returns number of bytes read on success, 0 on error. 236 */ 237 static size_t read_lba(struct parsed_partitions *state, 238 u64 lba, u8 *buffer, size_t count) 239 { 240 size_t totalreadcount = 0; 241 struct block_device *bdev = state->bdev; 242 sector_t n = lba * (bdev_logical_block_size(bdev) / 512); 243 244 if (!buffer || lba > last_lba(bdev)) 245 return 0; 246 247 while (count) { 248 int copied = 512; 249 Sector sect; 250 unsigned char *data = read_part_sector(state, n++, §); 251 if (!data) 252 break; 253 if (copied > count) 254 copied = count; 255 memcpy(buffer, data, copied); 256 put_dev_sector(sect); 257 buffer += copied; 258 totalreadcount +=copied; 259 count -= copied; 260 } 261 return totalreadcount; 262 } 263 264 /** 265 * alloc_read_gpt_entries(): reads partition entries from disk 266 * @state: disk parsed partitions 267 * @gpt: GPT header 268 * 269 * Description: Returns ptes on success, NULL on error. 270 * Allocates space for PTEs based on information found in @gpt. 271 * Notes: remember to free pte when you're done! 272 */ 273 static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state, 274 gpt_header *gpt) 275 { 276 size_t count; 277 gpt_entry *pte; 278 279 if (!gpt) 280 return NULL; 281 282 count = (size_t)le32_to_cpu(gpt->num_partition_entries) * 283 le32_to_cpu(gpt->sizeof_partition_entry); 284 if (!count) 285 return NULL; 286 pte = kmalloc(count, GFP_KERNEL); 287 if (!pte) 288 return NULL; 289 290 if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba), 291 (u8 *) pte, count) < count) { 292 kfree(pte); 293 pte=NULL; 294 return NULL; 295 } 296 return pte; 297 } 298 299 /** 300 * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk 301 * @state: disk parsed partitions 302 * @lba: the Logical Block Address of the partition table 303 * 304 * Description: returns GPT header on success, NULL on error. Allocates 305 * and fills a GPT header starting at @ from @state->bdev. 306 * Note: remember to free gpt when finished with it. 307 */ 308 static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state, 309 u64 lba) 310 { 311 gpt_header *gpt; 312 unsigned ssz = bdev_logical_block_size(state->bdev); 313 314 gpt = kmalloc(ssz, GFP_KERNEL); 315 if (!gpt) 316 return NULL; 317 318 if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) { 319 kfree(gpt); 320 gpt=NULL; 321 return NULL; 322 } 323 324 return gpt; 325 } 326 327 /** 328 * is_gpt_valid() - tests one GPT header and PTEs for validity 329 * @state: disk parsed partitions 330 * @lba: logical block address of the GPT header to test 331 * @gpt: GPT header ptr, filled on return. 332 * @ptes: PTEs ptr, filled on return. 333 * 334 * Description: returns 1 if valid, 0 on error. 335 * If valid, returns pointers to newly allocated GPT header and PTEs. 336 */ 337 static int is_gpt_valid(struct parsed_partitions *state, u64 lba, 338 gpt_header **gpt, gpt_entry **ptes) 339 { 340 u32 crc, origcrc; 341 u64 lastlba, pt_size; 342 343 if (!ptes) 344 return 0; 345 if (!(*gpt = alloc_read_gpt_header(state, lba))) 346 return 0; 347 348 /* Check the GUID Partition Table signature */ 349 if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) { 350 pr_debug("GUID Partition Table Header signature is wrong:" 351 "%lld != %lld\n", 352 (unsigned long long)le64_to_cpu((*gpt)->signature), 353 (unsigned long long)GPT_HEADER_SIGNATURE); 354 goto fail; 355 } 356 357 /* Check the GUID Partition Table header size is too big */ 358 if (le32_to_cpu((*gpt)->header_size) > 359 bdev_logical_block_size(state->bdev)) { 360 pr_debug("GUID Partition Table Header size is too large: %u > %u\n", 361 le32_to_cpu((*gpt)->header_size), 362 bdev_logical_block_size(state->bdev)); 363 goto fail; 364 } 365 366 /* Check the GUID Partition Table header size is too small */ 367 if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) { 368 pr_debug("GUID Partition Table Header size is too small: %u < %zu\n", 369 le32_to_cpu((*gpt)->header_size), 370 sizeof(gpt_header)); 371 goto fail; 372 } 373 374 /* Check the GUID Partition Table CRC */ 375 origcrc = le32_to_cpu((*gpt)->header_crc32); 376 (*gpt)->header_crc32 = 0; 377 crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size)); 378 379 if (crc != origcrc) { 380 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n", 381 crc, origcrc); 382 goto fail; 383 } 384 (*gpt)->header_crc32 = cpu_to_le32(origcrc); 385 386 /* Check that the my_lba entry points to the LBA that contains 387 * the GUID Partition Table */ 388 if (le64_to_cpu((*gpt)->my_lba) != lba) { 389 pr_debug("GPT my_lba incorrect: %lld != %lld\n", 390 (unsigned long long)le64_to_cpu((*gpt)->my_lba), 391 (unsigned long long)lba); 392 goto fail; 393 } 394 395 /* Check the first_usable_lba and last_usable_lba are 396 * within the disk. 397 */ 398 lastlba = last_lba(state->bdev); 399 if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) { 400 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n", 401 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba), 402 (unsigned long long)lastlba); 403 goto fail; 404 } 405 if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) { 406 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n", 407 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), 408 (unsigned long long)lastlba); 409 goto fail; 410 } 411 if (le64_to_cpu((*gpt)->last_usable_lba) < le64_to_cpu((*gpt)->first_usable_lba)) { 412 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n", 413 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), 414 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba)); 415 goto fail; 416 } 417 /* Check that sizeof_partition_entry has the correct value */ 418 if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) { 419 pr_debug("GUID Partition Entry Size check failed.\n"); 420 goto fail; 421 } 422 423 /* Sanity check partition table size */ 424 pt_size = (u64)le32_to_cpu((*gpt)->num_partition_entries) * 425 le32_to_cpu((*gpt)->sizeof_partition_entry); 426 if (pt_size > KMALLOC_MAX_SIZE) { 427 pr_debug("GUID Partition Table is too large: %llu > %lu bytes\n", 428 (unsigned long long)pt_size, KMALLOC_MAX_SIZE); 429 goto fail; 430 } 431 432 if (!(*ptes = alloc_read_gpt_entries(state, *gpt))) 433 goto fail; 434 435 /* Check the GUID Partition Entry Array CRC */ 436 crc = efi_crc32((const unsigned char *) (*ptes), pt_size); 437 438 if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { 439 pr_debug("GUID Partition Entry Array CRC check failed.\n"); 440 goto fail_ptes; 441 } 442 443 /* We're done, all's well */ 444 return 1; 445 446 fail_ptes: 447 kfree(*ptes); 448 *ptes = NULL; 449 fail: 450 kfree(*gpt); 451 *gpt = NULL; 452 return 0; 453 } 454 455 /** 456 * is_pte_valid() - tests one PTE for validity 457 * @pte:pte to check 458 * @lastlba: last lba of the disk 459 * 460 * Description: returns 1 if valid, 0 on error. 461 */ 462 static inline int 463 is_pte_valid(const gpt_entry *pte, const u64 lastlba) 464 { 465 if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) || 466 le64_to_cpu(pte->starting_lba) > lastlba || 467 le64_to_cpu(pte->ending_lba) > lastlba) 468 return 0; 469 return 1; 470 } 471 472 /** 473 * compare_gpts() - Search disk for valid GPT headers and PTEs 474 * @pgpt: primary GPT header 475 * @agpt: alternate GPT header 476 * @lastlba: last LBA number 477 * 478 * Description: Returns nothing. Sanity checks pgpt and agpt fields 479 * and prints warnings on discrepancies. 480 * 481 */ 482 static void 483 compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba) 484 { 485 int error_found = 0; 486 if (!pgpt || !agpt) 487 return; 488 if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) { 489 pr_warn("GPT:Primary header LBA != Alt. header alternate_lba\n"); 490 pr_warn("GPT:%lld != %lld\n", 491 (unsigned long long)le64_to_cpu(pgpt->my_lba), 492 (unsigned long long)le64_to_cpu(agpt->alternate_lba)); 493 error_found++; 494 } 495 if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) { 496 pr_warn("GPT:Primary header alternate_lba != Alt. header my_lba\n"); 497 pr_warn("GPT:%lld != %lld\n", 498 (unsigned long long)le64_to_cpu(pgpt->alternate_lba), 499 (unsigned long long)le64_to_cpu(agpt->my_lba)); 500 error_found++; 501 } 502 if (le64_to_cpu(pgpt->first_usable_lba) != 503 le64_to_cpu(agpt->first_usable_lba)) { 504 pr_warn("GPT:first_usable_lbas don't match.\n"); 505 pr_warn("GPT:%lld != %lld\n", 506 (unsigned long long)le64_to_cpu(pgpt->first_usable_lba), 507 (unsigned long long)le64_to_cpu(agpt->first_usable_lba)); 508 error_found++; 509 } 510 if (le64_to_cpu(pgpt->last_usable_lba) != 511 le64_to_cpu(agpt->last_usable_lba)) { 512 pr_warn("GPT:last_usable_lbas don't match.\n"); 513 pr_warn("GPT:%lld != %lld\n", 514 (unsigned long long)le64_to_cpu(pgpt->last_usable_lba), 515 (unsigned long long)le64_to_cpu(agpt->last_usable_lba)); 516 error_found++; 517 } 518 if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) { 519 pr_warn("GPT:disk_guids don't match.\n"); 520 error_found++; 521 } 522 if (le32_to_cpu(pgpt->num_partition_entries) != 523 le32_to_cpu(agpt->num_partition_entries)) { 524 pr_warn("GPT:num_partition_entries don't match: " 525 "0x%x != 0x%x\n", 526 le32_to_cpu(pgpt->num_partition_entries), 527 le32_to_cpu(agpt->num_partition_entries)); 528 error_found++; 529 } 530 if (le32_to_cpu(pgpt->sizeof_partition_entry) != 531 le32_to_cpu(agpt->sizeof_partition_entry)) { 532 pr_warn("GPT:sizeof_partition_entry values don't match: " 533 "0x%x != 0x%x\n", 534 le32_to_cpu(pgpt->sizeof_partition_entry), 535 le32_to_cpu(agpt->sizeof_partition_entry)); 536 error_found++; 537 } 538 if (le32_to_cpu(pgpt->partition_entry_array_crc32) != 539 le32_to_cpu(agpt->partition_entry_array_crc32)) { 540 pr_warn("GPT:partition_entry_array_crc32 values don't match: " 541 "0x%x != 0x%x\n", 542 le32_to_cpu(pgpt->partition_entry_array_crc32), 543 le32_to_cpu(agpt->partition_entry_array_crc32)); 544 error_found++; 545 } 546 if (le64_to_cpu(pgpt->alternate_lba) != lastlba) { 547 pr_warn("GPT:Primary header thinks Alt. header is not at the end of the disk.\n"); 548 pr_warn("GPT:%lld != %lld\n", 549 (unsigned long long)le64_to_cpu(pgpt->alternate_lba), 550 (unsigned long long)lastlba); 551 error_found++; 552 } 553 554 if (le64_to_cpu(agpt->my_lba) != lastlba) { 555 pr_warn("GPT:Alternate GPT header not at the end of the disk.\n"); 556 pr_warn("GPT:%lld != %lld\n", 557 (unsigned long long)le64_to_cpu(agpt->my_lba), 558 (unsigned long long)lastlba); 559 error_found++; 560 } 561 562 if (error_found) 563 pr_warn("GPT: Use GNU Parted to correct GPT errors.\n"); 564 return; 565 } 566 567 /** 568 * find_valid_gpt() - Search disk for valid GPT headers and PTEs 569 * @state: disk parsed partitions 570 * @gpt: GPT header ptr, filled on return. 571 * @ptes: PTEs ptr, filled on return. 572 * 573 * Description: Returns 1 if valid, 0 on error. 574 * If valid, returns pointers to newly allocated GPT header and PTEs. 575 * Validity depends on PMBR being valid (or being overridden by the 576 * 'gpt' kernel command line option) and finding either the Primary 577 * GPT header and PTEs valid, or the Alternate GPT header and PTEs 578 * valid. If the Primary GPT header is not valid, the Alternate GPT header 579 * is not checked unless the 'gpt' kernel command line option is passed. 580 * This protects against devices which misreport their size, and forces 581 * the user to decide to use the Alternate GPT. 582 */ 583 static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt, 584 gpt_entry **ptes) 585 { 586 int good_pgpt = 0, good_agpt = 0, good_pmbr = 0; 587 gpt_header *pgpt = NULL, *agpt = NULL; 588 gpt_entry *pptes = NULL, *aptes = NULL; 589 legacy_mbr *legacymbr; 590 sector_t total_sectors = i_size_read(state->bdev->bd_inode) >> 9; 591 u64 lastlba; 592 593 if (!ptes) 594 return 0; 595 596 lastlba = last_lba(state->bdev); 597 if (!force_gpt) { 598 /* This will be added to the EFI Spec. per Intel after v1.02. */ 599 legacymbr = kzalloc(sizeof(*legacymbr), GFP_KERNEL); 600 if (!legacymbr) 601 goto fail; 602 603 read_lba(state, 0, (u8 *)legacymbr, sizeof(*legacymbr)); 604 good_pmbr = is_pmbr_valid(legacymbr, total_sectors); 605 kfree(legacymbr); 606 607 if (!good_pmbr) 608 goto fail; 609 610 pr_debug("Device has a %s MBR\n", 611 good_pmbr == GPT_MBR_PROTECTIVE ? 612 "protective" : "hybrid"); 613 } 614 615 good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA, 616 &pgpt, &pptes); 617 if (good_pgpt) 618 good_agpt = is_gpt_valid(state, 619 le64_to_cpu(pgpt->alternate_lba), 620 &agpt, &aptes); 621 if (!good_agpt && force_gpt) 622 good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes); 623 624 /* The obviously unsuccessful case */ 625 if (!good_pgpt && !good_agpt) 626 goto fail; 627 628 compare_gpts(pgpt, agpt, lastlba); 629 630 /* The good cases */ 631 if (good_pgpt) { 632 *gpt = pgpt; 633 *ptes = pptes; 634 kfree(agpt); 635 kfree(aptes); 636 if (!good_agpt) 637 pr_warn("Alternate GPT is invalid, using primary GPT.\n"); 638 return 1; 639 } 640 else if (good_agpt) { 641 *gpt = agpt; 642 *ptes = aptes; 643 kfree(pgpt); 644 kfree(pptes); 645 pr_warn("Primary GPT is invalid, using alternate GPT.\n"); 646 return 1; 647 } 648 649 fail: 650 kfree(pgpt); 651 kfree(agpt); 652 kfree(pptes); 653 kfree(aptes); 654 *gpt = NULL; 655 *ptes = NULL; 656 return 0; 657 } 658 659 /** 660 * utf16_le_to_7bit(): Naively converts a UTF-16LE string to 7-bit ASCII characters 661 * @in: input UTF-16LE string 662 * @size: size of the input string 663 * @out: output string ptr, should be capable to store @size+1 characters 664 * 665 * Description: Converts @size UTF16-LE symbols from @in string to 7-bit 666 * ASCII characters and stores them to @out. Adds trailing zero to @out array. 667 */ 668 static void utf16_le_to_7bit(const __le16 *in, unsigned int size, u8 *out) 669 { 670 unsigned int i = 0; 671 672 out[size] = 0; 673 674 while (i < size) { 675 u8 c = le16_to_cpu(in[i]) & 0xff; 676 677 if (c && !isprint(c)) 678 c = '!'; 679 out[i] = c; 680 i++; 681 } 682 } 683 684 /** 685 * efi_partition(struct parsed_partitions *state) 686 * @state: disk parsed partitions 687 * 688 * Description: called from check.c, if the disk contains GPT 689 * partitions, sets up partition entries in the kernel. 690 * 691 * If the first block on the disk is a legacy MBR, 692 * it will get handled by msdos_partition(). 693 * If it's a Protective MBR, we'll handle it here. 694 * 695 * We do not create a Linux partition for GPT, but 696 * only for the actual data partitions. 697 * Returns: 698 * -1 if unable to read the partition table 699 * 0 if this isn't our partition table 700 * 1 if successful 701 * 702 */ 703 int efi_partition(struct parsed_partitions *state) 704 { 705 gpt_header *gpt = NULL; 706 gpt_entry *ptes = NULL; 707 u32 i; 708 unsigned ssz = bdev_logical_block_size(state->bdev) / 512; 709 710 if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) { 711 kfree(gpt); 712 kfree(ptes); 713 return 0; 714 } 715 716 pr_debug("GUID Partition Table is valid! Yea!\n"); 717 718 for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) { 719 struct partition_meta_info *info; 720 unsigned label_max; 721 u64 start = le64_to_cpu(ptes[i].starting_lba); 722 u64 size = le64_to_cpu(ptes[i].ending_lba) - 723 le64_to_cpu(ptes[i].starting_lba) + 1ULL; 724 725 if (!is_pte_valid(&ptes[i], last_lba(state->bdev))) 726 continue; 727 728 put_partition(state, i+1, start * ssz, size * ssz); 729 730 /* If this is a RAID volume, tell md */ 731 if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID)) 732 state->parts[i + 1].flags = ADDPART_FLAG_RAID; 733 734 info = &state->parts[i + 1].info; 735 efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid); 736 737 /* Naively convert UTF16-LE to 7 bits. */ 738 label_max = min(ARRAY_SIZE(info->volname) - 1, 739 ARRAY_SIZE(ptes[i].partition_name)); 740 utf16_le_to_7bit(ptes[i].partition_name, label_max, info->volname); 741 state->parts[i + 1].has_info = true; 742 } 743 kfree(ptes); 744 kfree(gpt); 745 strlcat(state->pp_buf, "\n", PAGE_SIZE); 746 return 1; 747 } 748